There are no assembly instructions included with the chair.  It's relatively easy to figure out how to assemble but becomes a huge problem when one of the screws that attaches the seat to the bar/frame is stripped and can't be used. 3 of 4 screws did attach. Then when you go to attach the leg system to the seat, it does not fit properly and the seat falls off of the legs!!!!! Must be missing a part or the black rubber end of the  "hydraulic system" should be removed!!!  Have no idea since there are no instructions.  A chair that costs this much should not have this many problems.  Not worth the cost.  Not happy